The present invention is concerned with a process for the manufacture of spherical or essentially spherical, practically dust-free, free-flowing, mechanically stable flavorant and odorant granulates having a narrow particle size distribution.
Under "spherical" there is to be understood in the present case a bead-like or an essentially bead-like material upon visual observation with the naked eye.
Flavorant granulates are known. EP 0070719 describes the manufacture of flavorant granulates which are manufactured in a conventional fluidized bed formed simply by the whirling-up of air. These products have, however, the disadvantages of an insufficient mechanical stability, the relatively large dust content and a limited flow capability.
The object of the present invention was a process which permits the manufacture of products which no longer have the described disadvantages and accordingly which are clearly preferred during their use, namely during incorporation into the material to be flavoured or perfumed. Foodstuffs, products consumed for pleasure and drinks, pharmaceuticals, cosmetic products, hygiene products, e.g. mouth hygiene products, diapers, soaps, detergents, household products etc. stand in the foreground.
In addition, the flavorant and odorant granulates obtainable in accordance with the invention can be provided in a second step in a simple manner with a coating without switching off or modifying the rotor-granulator which is now used in accordance with the invention or without the need to transfer product. The coating also aims at an improved encapsulation of the active substances, to achieve a modification, i.e. improvement in the solubility behaviour or a planned protective action.
Roto-granulators have hitherto been employed in the production of washing agent addivites, fertilizers and pharmaceutically active substances (see the company brochure GRCG Type 1-200 from the firm Glatt, Pratteln, Switzerland June 1992]).
The apparatus comprises essentially a fluidized bed apparatus and an arrangement for supplying and extracting air. It is conveniently e.g. a cylindrical vessel having a vertical rotating axis, the base of which rotates around the central axis. The cylinder casing is conveniently fixed. The rate of rotation is conveniently about 50-500/min. The core material provided in the process is set in motion by means of a rotating base plate. A relatively small amount of air passes through the (peripheral) annular clearance between the rotating base plate and fixed vessel wall and this together with the rotational motion of the base plate sets the material present in motion, i.e. "fluidizes". In comparison to earlier technology, which produces the required motion of the material only with the aid of air, now about 1/5--about 1/3 of the air is required in order to fluidize the solid which has been provided.